better code generation for `||=`; #3138

2 files changed, 24 insertions, 9 deletions

diff --git a/mrbgems/mruby-compiler/core/codegen.c b/mrbgems/mruby-compiler/core/codegen.c
index ced2d5a28..f68c04c85 100644
--- a/mrbgems/mruby-compiler/core/codegen.c
+++ b/mrbgems/mruby-compiler/core/codegen.c
@@ -1712,14 +1712,35 @@ codegen(codegen_scope *s, node *tree, int val)
       const char *name = mrb_sym2name_len(s->mrb, sym, &len);
       int idx;
 
-      codegen(s, tree->car, VAL);
+      if ((len == 2 && name[0] == '|' && name[1] == '|') &&
+          ((intptr_t)tree->car->car == NODE_CONST ||
+           (intptr_t)tree->car->car == NODE_CVAR)) {
+        int onerr, noexc, exc;
+        struct loopinfo *lp;
+
+        onerr = genop(s, MKOP_Bx(OP_ONERR, 0));
+        lp = loop_push(s, LOOP_BEGIN);
+        lp->pc1 = onerr;
+        exc = cursp();
+        codegen(s, tree->car, VAL);
+        lp->type = LOOP_RESCUE;
+        genop(s, MKOP_A(OP_POPERR, 1));
+        noexc = genop(s, MKOP_Bx(OP_JMP, 0));
+        dispatch(s, onerr);
+        genop(s, MKOP_A(OP_RESCUE, exc));
+        genop(s, MKOP_A(OP_LOADF, exc));
+        dispatch(s, noexc);
+      }
+      else {
+        codegen(s, tree->car, VAL);
+      }
       if (len == 2 &&
           ((name[0] == '|' && name[1] == '|') ||
            (name[0] == '&' && name[1] == '&'))) {
         int pos;
 
         pop();
-        pos = genop_peep(s, MKOP_AsBx(name[0] == '|' ? OP_JMPIF : OP_JMPNOT, cursp(), 0), NOVAL);
+        pos = genop_peep(s, MKOP_AsBx(name[0]=='|'?OP_JMPIF:OP_JMPNOT, cursp(), 0), NOVAL);
         codegen(s, tree->cdr->cdr->car, VAL);
         pop();
         gen_assignment(s, tree->car, cursp(), val);
diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index 7329747e2..a2add4247 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -709,13 +709,7 @@ new_masgn(parser_state *p, node *a, node *b)
 static node*
 new_op_asgn(parser_state *p, node *a, mrb_sym op, node *b)
 {
-  node *n = list4((node*)NODE_OP_ASGN, a, nsym(op), b);
-  if (op == mrb_intern_lit(p->mrb, "||") &&
-      ((intptr_t)a->car == NODE_CONST || (intptr_t)a->car == NODE_CVAR)) {
-    return new_rescue(p, n, list1(list3(list1(new_const(p, mrb_intern_lit(p->mrb, "NameError"))),
-                                        0, new_asgn(p, a, b))), NULL);
-  }
-  return n;
+  return list4((node*)NODE_OP_ASGN, a, nsym(op), b);
 }
 
 /* (:int . i) */